1. Field
This disclosure relates to local area networks that use a combination of two or more communications media, which may include both wireless and wired communications media.
2. Description of the Related Art
A variety of communications media and standards are available for use in network communications. These standards are usually defined in accordance with the seven-layer OSI (Open System Interconnect) model. The lowest layer of the OSI model is the physical layer, which defines how to transmit bits over a communications medium. In this patent, the term “communications media” means any media for conveying or transmitting information. Communications media include electrical wires, coaxial cables, optical fibers, and wireless communications using radio-frequency, optical, or acoustic carrier waves.
Standard physical layer protocols include various Institute of Electrical and Electronic Engineers (IEEE) Std. 802.3 “Ethernet” protocols (10BASE-T, 100BASE-T, etc.); wireless communications protocols in accordance with IEEE Std. 802.11, commonly called Wi-Fi®; SONET (synchronous optical network) protocols; and other protocols defined by an industry group or standard-setting authority. An emerging technology for network communications is power line communications (PLC), which may be in accordance with standards such as IEEE Std 1901-2010 or the International Telecommunications Union ITU-T G.hn standard. ITU-T G.hn is also a standard for phone line communications and communications over TV cable.
Many of these protocols define both the physical layer and the data link layer (the second lowest layer), as well as higher layers of the OSI model. The data link layer may be composed of logical link control and media access control (MAC) sublayers.
Throughout this description, elements appearing in figures are assigned three-digit reference designators, where the most significant digit is the figure number where the element is introduced. An element that is not described in conjunction with a figure may be presumed to have the same characteristics and function as a previously-described element having the same reference designator.